Powder-grain



622.777 Patented Apr. n, 1899. F. H. EECGAHIE.

POWDER GRAIN.

(Application filed May 15, 1896.)

4 Sheets-Sheet I.

(No Model.)

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4 Sheets-Sheet 2.

@No Model.)

@(Qda No. 622,777. Patented Apr. ll, I899. F. H. MGGAHIE.

POWDER GRAIN.

I {Application filed may 15, 1896.) (No Model.) 4 Sheets$heet 3.

Patented Apr. ll, I899.

F. H. MGGAHIE.

POWDER GRAIN.

(Application filed May 15, 1896.)

4 Sheets-Sheet 4.

{No Model.)

- lllllllllll rates FREDERICK n. MoGAl-IIE, or FARMINGDALE, NEWJERSEY,'ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE E. 1. DU FONT DE NEMOURS& COMPANY, or WILMINGTON, DELAYVARE.

PQWDER-GRMN.

fiPECIFIGATION forming part of Letters Patent N0. 622,777, dated April 11, 1899. Application filed May 15, 1896. serial No. 591,617. (Nospecimens.)

To ctZZ whom it may concern: The most serviceable of all the artilleryo.

Beitknown that LF. LEDERICK ILMCGAHIE, powders of the class (f smokelesspowders is a citizen of the United States of America, rea colloid nearlyall guncotton in the shape of siding at Farmingdale, county of Monmouth,multiperforated rods or grains. The success 5 State of New Jersey, haveinvented certain of this powder is due to its progressive rate new anduseful Improvements in Powderof burning, owing to the fact that theflame 55 Grains, of which the following is a-speciiicaof combustion canonly attack its surface.

tion. As the configuration of such a grain exposes The present inventionrelates to an imup'to a certain limit a constantly-increasing provedform of multiperforated powder rod burning-surface, it is evident thatthe presor grain. sure must be better maintained along the bore 60 Theobject of the invention is the producof agunthanwith powders hithertoused. The

tion of a more efiicient powder rod or grain perforationsin the old formof multiperforated particularly adapted to that class of colloidgrains-being circular in cross-section, as inpowders popularly known assmokeless. dicated in Fig. 7, the limit of increasing burn- Generallyspeaking, the improved form of ing-surface is reached when thecontiguous 65 powder consists of a rod or grain of any suitportions ofthe circular perforations merge able exterior contour, cylindrical,rectanguinto each other, and there are left at that molar, or polygonalin cross-section, embracing ment in the intracircular'spaces three-coraplurality of perforations of such shape and nered rods 0, (indicated bythe shaded porlocation as that when the rod or grain is tions,) thesides of which are concave orarcs 7o burned the walls of theperforations attacked of enlarged circles concentric with the axes bythe-flame of combustion will gradually of the original perforations c,and from this and progressively enlarge and will finally simomenttheresultant rods 0 of the original multaneously meet at the moment theentire grains burn with aconstantly-decreasingsurgrain is consumed,leaving no portion forsubface until the whole is consumed. This ob- 7 5sequent combustion on surfaces decreasing jectionable feature in thepracticabuse of in area. The means for making this new form multiperforated powder has been recognized; of powder may consist in one formin adie of but no solution of the dilficulty has, so far as suitableconstruction and configuration, as I am aware, been discovered.

will be hereinafter fully set forth. I have deviseda form of grain and ameans Theaccompanyingdrawingsillustrate pracfor making it which entirelyovercomes this ticalembodimentsoftheinvention,inwhieh inherent defect inmultiperforated powder Figures 1, 2, 3, and 4 are elevations of difandwhich will provide a progressive rate of 3 5 ferent forms of theimproved powder-grain. burning until the entire grain is consumed,

Fig. 5 is a side view of the grain of Fig. 1. this result being renderedpossible by the all- Fig. 6 is a modified form of the grain of Fig.important property of these colloid powders 1, with an exterior envelopor coating. Fig. to burn only from the surface. 7 is a diagram of theold form of multiper- One of the improved forms of grain deemed oforated grain, showing the portions which most desirable is shown inFigs. 1 and 5, and

cause the Subseqkent combustion on decreasconsists of a cylindricalstructure A, having 0 ing areas. Fig. 8 is a sectional elevation of aplurality of parallel longitudinal perforathe improved means for formingthe powder tions extending from end to end of the cylinrod or grain.Figs. SKand 8 are cross-secder. The shape and location of the perfora-45 tions on the lines 8 and S of Fig. 8, and Fig. tions to provide thedesired increasing burn- 0 is a bottom view of the die portion thereof.ing area up to the entire consumption of the 5 Fig. 10 is a sectionalelevation of a modified grain are determined by calculation based formof the die. Fig. 11 is a plan view thereon the required thickness of thepowder-wall of, and Fig. 12 a bottom View of the die. between theperforations and between the be .provided.

/ BEST AVAILABLE COPY perforations and'the exterior surface, whichthickness will depend upon the composition of the powder, the caliberand length of the rifle, and theconditions of loading. Thus, given acylindrical powder-grain, as in Fig. 1, in which the thickness of thepowder-wall shall be equal to two, (2,) a circular center hole a of adiameter equal to one (1) will first Then, taking the center of saidhole as an axis, provide the exteriorcontour or circumference a of thegrain with aradius equal to five and one-half times the diameteruof thecenter hole. Under equal conditions all the burning-surfaces of ahomogeneous grain-will be consumed in directions parallel with theoriginal surface attacked by the flame of combustion and to equalextents, so that if one (1) represents the extent to whichthe originalsurface shall reach during combustion (at which time the projectileshould be just leaving themuzzle of the ri lie) then the exteriorcircumference a and original diameter of the grain will have decreasedwhen burning an extent equal to one (1) and have reached the dottedcircle a and at the same time the central hole a will have increased anextent also equal to one (1) and have reached the dotted circle a Toprovide the other perforations 0, the remaining area of'the grainextending between the dotted circles a a is divided, say, into six equalparts bounded by the radial lines (1 The walls of these ;otherperforations may then be provided on short lines a, parallel with theradial lines at a distance therefrom in each direction equal to one,(1,) and pairs of these short lines will be connected to form the otherwalls of the perforations on lines concentric with the central hole, theinner wall at a distance outwardly equal to one (1) from the dottedcircle a and thelouterwall at a distance inwardly equal to one (1) fromthe dotted circle 0?, thus providing in this instancethe'segmental-shaped holes a. It will result from the shape and locationof these holes a that while the wall of "the center hole a is burningoutwardly toward the dotted circle a and the exterior circumference isburning inwardly toward the dotted circle a said holes a will each beprogressively increased in size, with their outer walls burning towardthe dotted circle a and the inner walls toward the dotted circle a? andthe side wallsburning in opposite directions toward the radial lines a,so that when the burning has progressed so that the dotted circles andthe entiregrain will have heen consumed,-

inig "absolutely nothing for further consu tion. it will thus beapparent that. as the powder is consumed each of the perforations of thegrain gradually and progressively creases in size, providing anincreasing hnrning area, until finally the perforations have sofarenlarged as to merge into one another at the moment the entire grain.is consumed.

It is obvious that the exterior contour on sea??? circumference a of vthe grain may be coated or enveloped or otherwise protected by some.non-explosiveor comparatively non-combustible material I), as indicatedin the modification Fig. 6, in which case, as the exterior of the grainwill not be attacked by the flame of combustion, the grain will have anarea bounded by the dotted circle a of 1, so that at the moment theperforations so far enlarge'as to merge into one another the envelopingmaterial I) will he reached and the entire grain consumed a J In thehexagonal form of grain shown in Fig. 2 substantially the sameconditions prevail,except that-in this case it is shown that thethickness of the grain may be varied so that the perforations (1. mayoriginally be smaller than is indicated in Fig. 1.

' In the modified form and larger grain shown in Fig. 3 the numberofperforations a is increased, two concentric rows-beingempioyed with anincreased effectt. e., the provision of a progressively-increasingburning area with a greater increased ratio until the entire grain isconsumed- In Fig. t the powdergrain is of rectangular form of anydesired depth,provided with rectangular perforations a so located thatan increasing burning is provided up to the moment the entire grain isconsumed. I

, The improved form of powder-grain will preferably b made by the use ofa press as ing a suitab ediethe powder mass while in a plastic conditionbeing forced through the die in the form of a more or less long perforated rod, which rod may be severed transversely into the desired lengthto form grains, A suitable press, together with a form of die, will nowbe described. 7

In the structure shown in Figs. 8 and 9 the die E is secured tothe endof a-suitabie cyiinder 0, into which the plastic powder mass is fed fromtime to time to be acted on and forced outward through the die oy theplum. ger'Dpopei-atedin any proper manner.

The' exterior contour of the powderrod or grain is formed by theinterior wall or mouth 10 of the die-confining cap or end piece 20 saidend piece having exterior screw-threads 11 to take into the threaded endof the presscylinder 0. The mandrels or other perforation-formingrods l213 are carried and sup-- the etx ea'ior annular portions of which areimmunised one against the other and rigidly confined between'a shoulder16 on the cylm radial lines are simultaneously reached the" def? a likeshoulder 1?" on the end piece 213%; so that both spiders with theirmandrels rieni the cylinder. I The mandrel 12, central one tor rormiugthe central perforation a, say, of powder-grain shown in Fi e 1. has ascrew- "threaded shank 18 taking into a threaded central hub 19 of thespider i i. the threaded shank from the baseor an inverted conicalh'eaddi of the mandrel proper. The

v be removed by unscrewing the end piece I mandrels 13 for forming therow of perforations a of the powder-grain shown in Fig. 1 are preferablyformed at the end of a cylindrical shell 22, screwthreaded into thethreaded central hub 23 of the spider and concentric with the centralmandrel 12, through whichshell said mandrel projects with the free endsof all the mandrels substantially in line with the end of the mouth 10of the die. v

The mandrels 13 may obviously be formed from the cylindrical shell 22 bycutting away portions of the shell in any proper machine,

the inner and outer wallsof the-cylindric I5 shell being perfectlyadapted without other preparation to the form of perforation a of Figs.1 and 3. Y For the perforations a of Fig. 2 the exterior wall of themandrels made from a cylindrical shell would of course have to beflattened to correspond with the shape of perforation shown.-

1 Where a powder-grain with the increased number of perforations a(shown in Fig. 3)

isto be produced, the spider carrying the mandrels 13 willbe preferablycarrying the outer concentric row of mandrels for the additional row ofperforationsof said Fig. 3. Thus, as shown in Figs. 10 to 12, the spider25 (like the spider 15) s' provided with the hub 23,supporting the shell22 and its mandrels 13, and in additionthereto is provided witha' secondhub 26, concentric with the hub 23, to which is screw-threaded thev endof a cylindrical shell 27, surrounding thes'hell 22 and likewise forrnedwith the mandrels 28, the two con centric sets of mandrels thus beingcarried by the one spider 25 and cooperating with a centralmandrel anddie-mouth, as described in connection with Fig 8, to produce apowder-gra'in of the character shown in Fig. 3.

The arms of the spiders 14, 15, and 25 in orderto not unduly impede theflow of the plastic mass to the exterior of the ma-ndrels and to thedie-mouth may be of the conical formation shown in the detail sectionsFigs. 8 and 8", the apex or thin edge being uppermost. The tubularcharacter of the 1. The herein-described multiperforaterl powdergrain,each of the perforations of which has a wall or walls parallel with theopposed wall of the adjacent perforations and a wall or walls parallelwith the exterior contour of the grain, and the perforations separatedfrom each other and from the exterior of the grain by equal thicknessesof powder, whereby increasing burning-surfaces are provided whichsimultaneously merge upon the consumption of the grain.

2. The herein described multiperforated powder-grain, each of theperforations of which. has a wall or walls parallel with the opposedwall of the adjacent perforationsand a wall or walls parallel with theexterior contour of the grain, and the perforations-separated from eachother and from the exterior of the grain by equal thicknesses of powder,whereby increasing burning-surfaces are provided which simultaneouslymerge upon the consumption of the grain, and said grain having anexterior'non-explosive envelop.

3. The herein described multiperforated powder-grain having a centralperforation and a surrounding concentric row of segmental shapedperforations, as set forth.

4. A multiperforated powder provided with a central perforation andsurrounding additional perforations, each of the surroundingperforations having two walls radial to the center of the cylinder asset forth.

In witness whereof I havehereunto signed my name in the presence of twowitnesses. FREDERICK H. MCGAHIE. 1

Witnessesr GEO. H. GRAHAM, E. L. TODD.

